Latest / Daniel and Kelly’s Extraordinary Universe / What would happen on earth if the moon disappeared?

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What would happen on earth if the moon disappeared? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Daniel, what's your favorite thing about looking at the
0:11
Speaker 1: night Scott? You know, I should probably say something inspirational
0:14
Speaker 1: about physics, etcetera. But honestly, being a family man, my
0:17
Speaker 1: favorite thing is that it means my kids are probably asleep.
0:22
Speaker 1: That's what the night sky means to you, that they're
0:24
Speaker 1: safely touch dead exactly? Or do you mean actually asleep?
0:27
Speaker 1: It's time for the adult portion of the day. That
0:30
Speaker 1: sounds that's sounds kind of racing, trust me, in my
0:33
Speaker 1: evening is not that exciting. But do you mean like
0:35
Speaker 1: they're in bed or they're just sleep or what makes
0:38
Speaker 1: it calm? Well, they're in bed and they're quiet. That's
0:40
Speaker 1: all I really care about. Honestly, whether they're asleep or
0:43
Speaker 1: not is their business now. But seriously, let's say, like
0:45
Speaker 1: you're leaving the night Skuy, what does it make you
0:48
Speaker 1: think of as a physicist, as an explorer, as a
0:51
Speaker 1: as a thinker. You know, it makes me think about vastness,
0:54
Speaker 1: the hugeeness of space, of course, you know, but also
0:58
Speaker 1: like the vastness of time. I mean, you can see
1:01
Speaker 1: time in the sky, know what. I love that when
1:03
Speaker 1: you look at the sky it's basically the same sky
1:06
Speaker 1: the people have been looking at and wondering about. For
1:09
Speaker 1: as long as people have been looking and wondering, you know,
1:12
Speaker 1: it hasn't changed that much. I have a question for you,
1:14
Speaker 1: what if it wasn't? What if our night sky changed?
1:18
Speaker 1: We Well, that'd be amazing. But as long as my
1:20
Speaker 1: kids stay in bed and stay quiet, I'd be cool
1:23
Speaker 1: with it. Hi am or Hammet cartoonists and the creator
1:41
Speaker 1: of PhD comics. Hi. I'm Daniel. I'm a particle physicist,
1:45
Speaker 1: a parent, and someone who likes to look up at
1:47
Speaker 1: the night sky and enjoy the quiet, vastness of space.
1:51
Speaker 1: And something we also share in comming is that we're
1:53
Speaker 1: are the co authors of the book We Have No Idea,
1:55
Speaker 1: a guide to the Unknown Universe. So if you are
1:58
Speaker 1: wondering about it, we don't know what physicists I have
2:02
Speaker 1: no idea about in our great, big universe. Please check
2:05
Speaker 1: out that book. It's a lot of fun and it
2:07
Speaker 1: features a lot of Jorges hilarious cartoons, so check it out.
2:11
Speaker 1: It's what neither a physicist nor a cartoonist knows about
2:14
Speaker 1: the universe. It also features a lot of Daniel's hilarious physics,
2:18
Speaker 1: so if you're into both hilarities, please check it up.
2:23
Speaker 1: But today, welcome to our podcast Daniel and Jorge Explain
2:26
Speaker 1: the Universe, a production of I Heart Radio. That's right,
2:29
Speaker 1: our podcast in which we think about all the things
2:31
Speaker 1: that are surrounding us, all the things up in the
2:33
Speaker 1: sky and down here on Earth, and try to explain
2:36
Speaker 1: them to you in a way that makes you laugh
2:37
Speaker 1: and hopefully illuminates your understanding of the world around us. Yeah,
2:41
Speaker 1: and we also think about the big what if questions
2:45
Speaker 1: in the universe, or if we can't use what if
2:47
Speaker 1: because it's copyrighted by Random Monroe of XKCB, we also
2:52
Speaker 1: tackle the what would happen is of the universe. We
2:55
Speaker 1: consider ourselves sort of breeding ground for the next generation
2:59
Speaker 1: of disaster movies by Michael Bay. You've done the Huge Shark,
3:03
Speaker 1: You've done the Crazy Storm. What's next, the big Asteroid?
3:08
Speaker 1: That's right, he's done that already, So we are just
3:10
Speaker 1: generating ideas for the next summer blockbuster. I think it's
3:14
Speaker 1: something a lot of people maybe wonder about out there.
3:17
Speaker 1: You know, what could be the next huge thing that
3:19
Speaker 1: could happen in this crazy, chaotic universe that might affect
3:23
Speaker 1: my life? And you don't have to speculate. I know
3:25
Speaker 1: the people out there wonder because they write to us
3:27
Speaker 1: about it. We get emails people asking us. For example,
3:31
Speaker 1: we did an episode recently about what would happen if
3:33
Speaker 1: the Sun became a black hole? That's an honest question
3:36
Speaker 1: that a bunch of people wrote in. People wonder about
3:38
Speaker 1: these things. It's on people's minds. You know, things around
3:42
Speaker 1: us seems stable, but what if something happened? And so
3:45
Speaker 1: this might be another one in our series of what
3:48
Speaker 1: would happen if and so to be on the podcast,
3:50
Speaker 1: we are going to be answering the question what would
3:58
Speaker 1: happen if the Earth lost its moon? Goodbye, mone, goodnight Moon.
4:04
Speaker 1: That's right, although these days, you know you have to
4:06
Speaker 1: say not to say good night to the moon. You
4:08
Speaker 1: have to say good night to the moon. And it's
4:11
Speaker 1: first colonizers by the Chinese. What do you mean there
4:15
Speaker 1: are living things on the moon now because of us? Yes? Uh.
4:19
Speaker 1: The Israeli's crash landed a probe on the moon, and
4:24
Speaker 1: on that probe we're tarte grades, little water bears, and
4:29
Speaker 1: so now we are just awaiting our lunar overlords, the
4:33
Speaker 1: coming of the Tartar Grade civilization. Oh my god, what
4:39
Speaker 1: a disaster, you know, I know, So be careful with
4:43
Speaker 1: your science, folks, you may accidentally seed a new civilization
4:47
Speaker 1: which destroys ours. Oh my good and Tarti grades are
4:50
Speaker 1: super scary. Oh they're so cute. We're gonna do an
4:53
Speaker 1: episode about Tartar grades in the next few weeks, so
4:56
Speaker 1: tune in for that one. But to think about it,
4:58
Speaker 1: as we talked about tonight, Remember the Moon is no
5:00
Speaker 1: longer a lifeless rock. It is now home to about
5:03
Speaker 1: a hundred little targegrades. Do you think they deserve their
5:06
Speaker 1: own country? I think Donald Trump will probably try to
5:09
Speaker 1: buy it. Yeah, Hey, if I can buy Greenland, why
5:13
Speaker 1: can't I buy the Moon. They'll flash a signed they'll
5:16
Speaker 1: make a formation on the surface of the Moon saying
5:18
Speaker 1: we are not for We're not for sale exactly. But
5:21
Speaker 1: it's an interesting question. You know, the moon is a
5:23
Speaker 1: big fixture in our lives, in our skies, in mythology,
5:27
Speaker 1: in romance. So what would happen sort to the human
5:30
Speaker 1: psyche and to life on Earth if the Earth lost
5:34
Speaker 1: its moons. It's a totally reasonable question. And you're saying
5:37
Speaker 1: this was a listener question as well. Somebody some people
5:39
Speaker 1: wrote this in yeah. Absolutely. People wrote this in and
5:42
Speaker 1: and wanted to know, And as soon as I read it,
5:44
Speaker 1: I thought that's a good question. I wonder how life
5:47
Speaker 1: would change on the on the surface of the Earth
5:49
Speaker 1: if we lost our moon. So I had to do
5:51
Speaker 1: some research. It was a lot of fun actually, so
5:52
Speaker 1: thank you folks for reading in this questions in aside, Daniel,
5:55
Speaker 1: I think that's the title of our third book, what
5:58
Speaker 1: would happen? What would happen? If? What would happen if
6:00
Speaker 1: a physicist and a cartoonists got paid to make three books?
6:05
Speaker 1: It would never happen. But I just wanted to get
6:08
Speaker 1: a review of our book from one of the hard
6:10
Speaker 1: grades on the moon. It's a life goal for me.
6:13
Speaker 1: So that's what we will be talking about today, is
6:15
Speaker 1: the question what would happen if the Earth lost its moon?
6:18
Speaker 1: Like if it suddenly disappeared, Daniel, or if it, you know,
6:21
Speaker 1: got knocked off and flew off or what do you
6:23
Speaker 1: think they were thinking when they asked the question. I
6:25
Speaker 1: don't know. I read a book recently by Neil Stevenson.
6:28
Speaker 1: It's a great book. It's called Seven Eaves, in which
6:30
Speaker 1: is the moon is demolished and all the rubble rains
6:34
Speaker 1: down on Earth. That's pretty bad scenario. So it might
6:37
Speaker 1: be that people are reading that book and wondering about it.
6:39
Speaker 1: Um or you know, just if the moon was like
6:42
Speaker 1: flung out in the space and got hit by an
6:43
Speaker 1: aster and deflected. And there's lots of different scenarios, but
6:46
Speaker 1: we'll dig into all of them. Wasn't that also a
6:48
Speaker 1: plot point in Avengers in Finny War, like Thanos reaches
6:52
Speaker 1: out and he grabs a moon and he brings it
6:53
Speaker 1: down on the Avengers. I do watch these movies, but
6:57
Speaker 1: they're like seventeen hours long, so I don't remember every
6:59
Speaker 1: plot point. But that's a pretty interesting question. And I
7:03
Speaker 1: imagine people think a lot of things would happen, or
7:05
Speaker 1: maybe nothing would happen. Yeah. So, actually, before I didn't research,
7:09
Speaker 1: before I even had an idea of my own, I
7:11
Speaker 1: went out and I asked folks what they thought would
7:14
Speaker 1: happen if the Earth lost its moon? And where were
7:16
Speaker 1: you in the world when you ask these questions, or
7:19
Speaker 1: even on the way you were as I was crash
7:22
Speaker 1: landing on the Moon when I asked these questions. No, um,
7:24
Speaker 1: here these questions were answered in some combination of Heathrow
7:27
Speaker 1: Airport and random cities in Portugal. Cool. So think about
7:31
Speaker 1: it for a second. What do you think would happen
7:33
Speaker 1: if the Earth lost its moon? Here's what people had
7:36
Speaker 1: to say. We wouldn't have moonlight. Well, I guess the
7:41
Speaker 1: tides would be out of balance and we should have
7:44
Speaker 1: floods coming. Yeah, because the whole stability of the whole
7:49
Speaker 1: system will fail, and then the Earth will lose the
7:53
Speaker 1: momentum and the oceans will I don't know what, but
7:58
Speaker 1: it's not possible to life on Earth without the moon.
8:04
Speaker 1: Life on Earth could theoretically survive. It is possible we
8:08
Speaker 1: could survive without a moon. However, climates would be much
8:10
Speaker 1: more unstable. I think it wouldn't be too bad for
8:16
Speaker 1: life on Earth except for those title creatures. Does the
8:19
Speaker 1: moon impact our seasonal change? No, I don't think so,
8:23
Speaker 1: although at nighttime it does make the evening flowers blue.
8:29
Speaker 1: All right, it seems like only bad things would happen.
8:33
Speaker 1: That's what people guessed. But he said, like, great, I
8:36
Speaker 1: hate the moon, Good riddance. Yeah, that's true. The moon
8:40
Speaker 1: has a good good Um, it's pretty favorable. I guess.
8:43
Speaker 1: I wonder if people ever do surveys like rate the
8:45
Speaker 1: favorability or unfavorability of astronomical objects. What's the most popular
8:50
Speaker 1: place to vote for this candidate or for the moon?
8:53
Speaker 1: Who would you want to be as your president? But
8:55
Speaker 1: what do you think is the most popular astronomical object?
8:58
Speaker 1: But if you ask people like which object and this
9:00
Speaker 1: guy would you delete if you had to delete one?
9:03
Speaker 1: Because which is the least popular aspect of object? Least popular?
9:08
Speaker 1: It's like those surveys online like what's your most popular
9:12
Speaker 1: movie that you love or the most popular movie that
9:15
Speaker 1: you hate? Yeah? Which all so writing folks, and let
9:17
Speaker 1: us know which astronomical object do you love to hate? Pluto?
9:21
Speaker 1: Probably poor Pluto? Um, but yeah, people people mostly said
9:27
Speaker 1: negative things would happen, right, nobody would be happy if
9:29
Speaker 1: the moon went away. And there's a big spectrum of
9:31
Speaker 1: possible outcomes here, Like the person who said we wouldn't
9:34
Speaker 1: have moonlight, like that's a disaster. You always like the
9:39
Speaker 1: technical answers, the trivial technical answers, Right, Well, if we
9:42
Speaker 1: didn't have a moon, we wouldn't have a moonlight. Technically true, yes,
9:47
Speaker 1: but do you think he meant that more like romantically?
9:49
Speaker 1: That like romance would be affected on Earth if there
9:52
Speaker 1: was no moonlight. It probably would be. Yeah, they'd probably
9:55
Speaker 1: be a different cycle of of conception and birth if
9:58
Speaker 1: there wasn't a moonlight icon um. But yeah, that's a
10:01
Speaker 1: great question. We'll be talking about what would happen physically, right,
10:05
Speaker 1: not necessarily biologically or romantically, but kind of like, how
10:09
Speaker 1: would the physics of our everyday life change if the
10:11
Speaker 1: Moon suddenly disappeared? Well, Daniel, let's step through it first.
10:15
Speaker 1: First of all, could it happen, Like, could our moon
10:17
Speaker 1: just disappear or move away or float away? There are
10:21
Speaker 1: lots of ways that we could lose our moon, right, um.
10:24
Speaker 1: Number one, if something hits the Moon, you know, really
10:27
Speaker 1: big asteroid or something. The Moon is an orbit around
10:30
Speaker 1: the Earth, but that's a little bit delicate, right. It's stable,
10:32
Speaker 1: but if it gets knocked out of orbit, it's pretty
10:35
Speaker 1: tough to get back into orbit. So yeah, you could
10:37
Speaker 1: get deflected. You mean, like an orbit is a very
10:40
Speaker 1: delicate thing, right, Like it's something that you could easily
10:43
Speaker 1: fly away or crashing into the planet if you disturb
10:46
Speaker 1: the orbit. Yeah, exactly, of all the possible trajectories around
10:49
Speaker 1: the planet, there's a very tiny fraction them that are
10:52
Speaker 1: a stable orbit, right, And so you change your trajectory,
10:55
Speaker 1: and you know, pretty sure soon you're sling shotting around
10:57
Speaker 1: the planet and then off into space or something. But
11:00
Speaker 1: you know, the Moon is hit all the time, that's
11:02
Speaker 1: why it's covered in craters. Usually it's just hit by
11:04
Speaker 1: a little rock and it doesn't change its motion significantly.
11:07
Speaker 1: But there are bigger rocks out there, and if one
11:09
Speaker 1: of them hit the Moon, then it could get deflected
11:11
Speaker 1: into outer space. Sure, how big do you think it
11:13
Speaker 1: would of a rock would it take to knock the
11:17
Speaker 1: Moon out of orbit? I haven't done any calculations, but
11:20
Speaker 1: you know, I think it has to be pretty substantial.
11:21
Speaker 1: You know, you're talking something like, you know, hundreds of
11:24
Speaker 1: meters wide are really a really pretty big solid rock.
11:27
Speaker 1: And we're sort of I heard also we're kind of
11:29
Speaker 1: losing the Moon anyways, Like the Moon doesn't want to
11:32
Speaker 1: be around really, it's sort of edging slowly for another
11:36
Speaker 1: planet in a way out of the party. They're like,
11:43
Speaker 1: all right, you guys are kind of crazy. I am
11:46
Speaker 1: gonna slowly move over to Mars because yeah, there's a
11:51
Speaker 1: good party going on on Venus. So see you later.
11:54
Speaker 1: Text you. Um, No, we're losing the Moon. It's not
11:57
Speaker 1: actually in a totally stable orbit. It's getting further away
12:02
Speaker 1: every year, but just by a tiny amount, just by
12:04
Speaker 1: a few centimeters. I looked it up. It's about four
12:07
Speaker 1: centimeters per year. And that's just the way it is.
12:09
Speaker 1: It's it's like in an orbit that is not stable.
12:12
Speaker 1: It's not in an orbit that self corrects or stays
12:15
Speaker 1: in its lane the whole time. It's like in a
12:18
Speaker 1: spiral outward away from the Earth. That's right. And you
12:21
Speaker 1: have to remember that the Earth and the Moon are
12:22
Speaker 1: a system, right. They're both orbiting the center of mass
12:26
Speaker 1: of the Earth of the Moon. Like imagine if the
12:28
Speaker 1: Moon and the Earth at the same mass, then their
12:31
Speaker 1: center of mass would be between them, literally, and they
12:34
Speaker 1: would both be moving around that point. But they're not
12:37
Speaker 1: the same mass. The Earth is much much heavier than
12:39
Speaker 1: the Moon, and so the center of mass of the
12:41
Speaker 1: two is closer to the center of the Earth. So
12:43
Speaker 1: but the two are really orbiting this point that's a
12:46
Speaker 1: slightly offset from the center of the Earth. And they're
12:49
Speaker 1: both spinning. So it's a big complicated system and energy
12:52
Speaker 1: is moving from one part of it to another, and
12:54
Speaker 1: so the Moon's rotation gets further out right. Um, But
12:59
Speaker 1: that all so means it gets more angular momentum. So
13:02
Speaker 1: the angle momentum has to come from somewhere. So as
13:06
Speaker 1: the Moon get drifts away, the Earth actually slows down
13:09
Speaker 1: a little bit. I mean the days get longer. Yeah,
13:11
Speaker 1: it's complicated, it's complicated, and so this you know, this
13:14
Speaker 1: whole system is not entirely stable, but it's a little
13:17
Speaker 1: bit stable. It actually turns out it's more stable. You
13:20
Speaker 1: get fewer fluctuations. We'll talk about it more in depth later,
13:23
Speaker 1: but it plays a big role in keeping the Earth
13:25
Speaker 1: in a sort of a stable rotation and and spin.
13:28
Speaker 1: I have been feeling like that are my days are
13:30
Speaker 1: are getting longer? You know, I just don't have the
13:34
Speaker 1: same energy I had before when I was younger. I
13:36
Speaker 1: don't know why you need more bananas. Most people feel
13:39
Speaker 1: like as they get older, the days just fly by.
13:42
Speaker 1: So that's one way the Moon could disappear. It could
13:44
Speaker 1: literally get knocked off course and fly away, or it
13:48
Speaker 1: is sort of slowly moving away. What are some other
13:51
Speaker 1: ways of the moon we could lose the moon? Well,
13:53
Speaker 1: the most catastrophic would be if it got hit by
13:55
Speaker 1: a rock and it didn't get deflected into space, but
13:57
Speaker 1: it got like broken up the Moon and is is
14:00
Speaker 1: you know, not as like strong as the Earth is
14:02
Speaker 1: size well held together. It's more of a pile of
14:05
Speaker 1: rubble than the Earth is because it doesn't have like
14:08
Speaker 1: inner magma and all that stuff, and so it could
14:11
Speaker 1: get broken up. And that's exactly what happens in that
14:14
Speaker 1: novel we were talking about earlier, seven Eves. Neil Stevenson
14:17
Speaker 1: does like fantastic research for his novels. I've never found
14:20
Speaker 1: a physics mistake in any of them, and I read
14:21
Speaker 1: them very carefully. And in that people at first were like, wow, cool,
14:25
Speaker 1: Look the Moon is exploding and there's all these shooting stars.
14:29
Speaker 1: But then quickly they realized, oh, this is just a
14:31
Speaker 1: bunch of rocks raining down on the Earth, and that's
14:33
Speaker 1: not good. The Moon turned into shooting stars and all
14:37
Speaker 1: that rained down on the Earth, it would heat of
14:38
Speaker 1: the atmosphere and a lot of those pieces would land,
14:41
Speaker 1: and you know, it's like getting hit by a by
14:44
Speaker 1: a planet killer. Would it necessarily crash into Earth? Like
14:47
Speaker 1: wouldn't like if the Moon cracked into two, wouldn't necessarily
14:50
Speaker 1: crash down? Or would the two houses keep going around
14:53
Speaker 1: the same orbit. It depends a lot on how the
14:55
Speaker 1: cracking happens. If you like exactly cracking in place, then yeah,
14:58
Speaker 1: they could keep orbiting just sort of cracked. But if
15:01
Speaker 1: it's a big collision, then some of it's going to
15:04
Speaker 1: get blown out into space, and some of it's gonna
15:06
Speaker 1: turn into a ring around the Earth because some of
15:08
Speaker 1: it will find a stable orbit, but a lot of
15:10
Speaker 1: it will just fall into the gravity well of Earth
15:12
Speaker 1: and land on Earth and kill a bunch of people.
15:15
Speaker 1: So not a happy scenario. So don't shoot the moon.
15:18
Speaker 1: Don't shoot the moon. That's right. Then shoot for the
15:20
Speaker 1: moon or add the moon. Unless you're playing hard, you're
15:23
Speaker 1: welcome to shoot the moon, but if you are in
15:25
Speaker 1: possession of a moon busting rocket, please do not shoot
15:29
Speaker 1: the moon. Alright, So it could maybe happen, And so
15:32
Speaker 1: let's dig into what would happen if the Moon disappeared,
15:36
Speaker 1: either by some physical process or just in our imaginations,
15:39
Speaker 1: if somebody snapped their finger and their moon just disappeared.
15:43
Speaker 1: What would happen to us here on Earth? But first
15:45
Speaker 1: let's take a quick break, all right, Daniel, we're talking
16:00
Speaker 1: about what would happened of the moon disappeared, and from
16:03
Speaker 1: a physics point of view, what would happen to the
16:06
Speaker 1: Earth if the Moon suddenly flew away or suddenly, um,
16:11
Speaker 1: I don't know, collapse, if the masters of the simulation
16:14
Speaker 1: just deleted it somehow. Yeah. Well, one of the most
16:18
Speaker 1: immediate things the effects of the Moon on life on Earth,
16:21
Speaker 1: of course, is it's gravity. Right. The Moon is a
16:24
Speaker 1: big ball of stuff and it has gravity, and that
16:27
Speaker 1: gravity pulls on the Earth, and it's a lot of
16:30
Speaker 1: people probably know that Moon causes tides on the Earth
16:33
Speaker 1: because it's pulling on the water that's on the Earth,
16:36
Speaker 1: and it's literally lifting it up a little bit off
16:39
Speaker 1: the surface, like sucking up the water up right. Yeah, exactly.
16:43
Speaker 1: Remember how gravity works, It depends on the distance, right,
16:46
Speaker 1: So the closer you are to the Moon, the stronger
16:49
Speaker 1: the force of the Moon on you, and so on
16:51
Speaker 1: the close side of the Earth, right, things are getting
16:54
Speaker 1: pulled harder than on the far side of the Earth.
16:56
Speaker 1: What happens is that every object ends up becoming sort
16:59
Speaker 1: of not spherical, but look more like an ellipse al, right,
17:02
Speaker 1: where the stuff that's on the closer side gets pulled up,
17:05
Speaker 1: you know, to be closer, and the stuff that's on
17:07
Speaker 1: the farther side isn't getting pulled as hard, and so
17:10
Speaker 1: it stretches out sort of long ways that way, so
17:14
Speaker 1: the Earth, instead of being a sphere, becomes a little obloid,
17:17
Speaker 1: both closer to the Moon and away from the Moon.
17:20
Speaker 1: That's where tides. That's where tides come from. Right, it's
17:22
Speaker 1: not it's not the because the moon is going around
17:26
Speaker 1: the Earth or both both things are. And the reason
17:28
Speaker 1: the tides change is because the Moon is going around
17:30
Speaker 1: the Earth and the tides follow it. Right, And uh,
17:33
Speaker 1: you know the reason it's the water is just because
17:36
Speaker 1: water is easier to move than rock. Right. It does
17:39
Speaker 1: also slightly squeeze the Earth and change the shape of
17:42
Speaker 1: the Earth, but that's a much smaller effect than just
17:45
Speaker 1: changing the levels of the ocean, because obviously water is
17:48
Speaker 1: much easier to squeeze than rock. I always wonder what
17:50
Speaker 1: sort of actually happening when the tides go up and down,
17:53
Speaker 1: you know, like it's it's the moon pulling on the
17:56
Speaker 1: water and so the water becomes less dense or you
18:01
Speaker 1: know what I mean, Like how does it go up?
18:04
Speaker 1: It's more about where the water is on Earth. Right,
18:07
Speaker 1: the you have you have the huge ocean, and all
18:09
Speaker 1: the oceans are basically connected and sea level is not
18:12
Speaker 1: a constant all the way around the Earth. Right, Sea
18:16
Speaker 1: level is not the same distance from the center of
18:18
Speaker 1: the Earth everywhere around the Earth. Because of the tides.
18:22
Speaker 1: Some of the water is getting gathered together into a bigger,
18:25
Speaker 1: deeper pile on some places, and it's getting slurped up
18:28
Speaker 1: from other places. So you get less water in the
18:30
Speaker 1: oceans on the sides and more water in the oceans
18:33
Speaker 1: on the moon side and on the opposite side. It's
18:35
Speaker 1: like it's recruiting water to where the Moon is. Yeah, exactly,
18:39
Speaker 1: Like say you took all the water and you put
18:41
Speaker 1: it in the Pacific Ocean, all the water from all
18:43
Speaker 1: the other oceans, and put it in the Pacific Ocean.
18:45
Speaker 1: Obviously that ocean would be deeper and the other ones
18:48
Speaker 1: would be shallower. It's basically that on a much smaller scale.
18:51
Speaker 1: So it's not a density thing, no, like there's less
18:54
Speaker 1: gravity or more. Yeah, but the water it's kind of cool,
18:56
Speaker 1: like the Moon is lifting the water, right, it's like
19:00
Speaker 1: gathering the water together into a pile. Um. That's it's
19:03
Speaker 1: a real size, you know. It sort of blows my mind.
19:05
Speaker 1: The moon is big enough, given how far away it
19:08
Speaker 1: is to actually like make piles of stuff on Earth
19:11
Speaker 1: just due to its gravity. Yeah, that's true. I mean
19:13
Speaker 1: it's a little circle in the sky and yet it's
19:15
Speaker 1: pulling a bunch of water into space. Yeah, it's a
19:20
Speaker 1: it's a big effect. And you know, people, um, some
19:22
Speaker 1: biologists give tides a big role in the development of life. Yeah,
19:28
Speaker 1: because one theory goes that, you know, in the sort
19:30
Speaker 1: of primordial soup rehabl these organic materials float around in oceans,
19:34
Speaker 1: that the tidal regions are the best place for life
19:37
Speaker 1: to start because the water is sort of mixing a lot, right,
19:40
Speaker 1: you get the tides coming in and out, and you're
19:42
Speaker 1: getting a lot of waves and splashing, and you get
19:45
Speaker 1: like periods, Yeah, a lot of churn exactly. And so
19:48
Speaker 1: I mean I think it's just speculation. I think people
19:51
Speaker 1: think that tides play a role in the development of life.
19:54
Speaker 1: You know, we can't go back and do the other
19:55
Speaker 1: experiment like delete the moon, run the Earth simulation and
19:58
Speaker 1: see if life takes long reach developed. But it's a
20:01
Speaker 1: cool idea, right, I mean, like life wouldn't just develop
20:03
Speaker 1: in a lake or a pond. Yeah, they sort of
20:06
Speaker 1: you need that sort of like motion to get things going.
20:09
Speaker 1: And also they noticed that these brackish ecosystems where you
20:13
Speaker 1: mix fresh and salt water and those get mixed due
20:15
Speaker 1: to tides, those that have the most diversity. And so
20:18
Speaker 1: I think that's another argument that the origin of life
20:20
Speaker 1: on Earth was affected by tides. All right, So if
20:23
Speaker 1: we didn't have the Moon, we wouldn't have ties, not quite.
20:26
Speaker 1: That's the fascinating thing is that you delete the Moon,
20:30
Speaker 1: tides are not gone. They're just smaller. And the reason
20:34
Speaker 1: is that we also have tides because of the Sun. What, Yeah,
20:38
Speaker 1: the Sun. It makes perfect sense, right. The Sun is
20:42
Speaker 1: much further away but much much huger than the Moon,
20:46
Speaker 1: and it also pulls on the Earth, obviously, and so
20:49
Speaker 1: it pulls stuff closer to it more strongly and stuff
20:52
Speaker 1: on the opposite side less strongly, and so it does
20:55
Speaker 1: the same thing to the Earth's oceans that the Moon does,
20:58
Speaker 1: but of course in a slightly different angle. Right, So
21:00
Speaker 1: you have the tides on Earth are complicated because you've
21:03
Speaker 1: got the little tides from the Sun and you've got
21:06
Speaker 1: the big tides from the Moon. And you know, that's
21:08
Speaker 1: why the tides sometimes are smaller than others. Wow, I
21:11
Speaker 1: had no idea, and we thought about it before it's
21:14
Speaker 1: I guess, you know, I guess the sun. It seems
21:16
Speaker 1: so far away and so little in the sky, but
21:18
Speaker 1: it's really swinging the earth around like a slingshot, and
21:22
Speaker 1: so some of them must affect the water on the surface.
21:24
Speaker 1: Absolutely does. So we would still have tides without the moon.
21:28
Speaker 1: We just wouldn't have as strong a tide, and the
21:30
Speaker 1: tides will be more regular because we have this complicated
21:33
Speaker 1: two body effects where you have two different things with
21:35
Speaker 1: two different periods, sometimes adding up to each other, sometimes
21:39
Speaker 1: contradicting each other. Right, so we have more complicated tides
21:42
Speaker 1: and larger tides because we have the moon and the sun.
21:45
Speaker 1: So we would have smaller tides or like half as
21:48
Speaker 1: much or like a tent. What do you think. I
21:51
Speaker 1: think it's about a quarter. Yeah, I think the moon
21:53
Speaker 1: is the majority of the tides, but the sun is
21:55
Speaker 1: a is a non negligible effect. So maybe we wouldn't
21:58
Speaker 1: miss it in that way, or maybe life could have
22:00
Speaker 1: still developed without the moon. Yeah, probably probably. And the
22:04
Speaker 1: moon and the tides have a lot of effect on
22:07
Speaker 1: the atmosphere as well, right, not just the water, but
22:10
Speaker 1: it affects the tides and and the just the gravitational
22:13
Speaker 1: pull of the Moon. It squeezes the atmosphere and affects
22:15
Speaker 1: things like global currents and uh, and so you get
22:19
Speaker 1: a lot more mixing just in general in the atmosphere
22:22
Speaker 1: because you have the Moon. And so people speculate that
22:25
Speaker 1: if you didn't have the Moon, not only would you
22:27
Speaker 1: not have tides, you have different patterns of global currents
22:29
Speaker 1: and you have stronger regional weather patterns because it wouldn't
22:32
Speaker 1: be as much sort of global mixing and evening out
22:35
Speaker 1: of stuff, all right, so it would affect the tides,
22:37
Speaker 1: but maybe not completely. And what else would happen if
22:40
Speaker 1: the moon disappeared, Well, obviously we wouldn't have eclipses, right,
22:44
Speaker 1: Like you know, without the moon, you can't get the
22:46
Speaker 1: Moon's shadow on the Earth either kind of eclipse, like
22:49
Speaker 1: a lunar eclipse. That's true, you need the moon for both.
22:54
Speaker 1: And you might scoff at that, but you know, eclipses
22:56
Speaker 1: are they're they're kind of amazing events. I had the
22:59
Speaker 1: opportunity to be in the full eclipse region for the
23:03
Speaker 1: last one, and I was shocked at how how sort
23:07
Speaker 1: of deeply spiritual event it was for me, somebody who's
23:09
Speaker 1: not really very spiritual at all. And I think that
23:12
Speaker 1: eclipses in history have also inspired a lot of thinkers
23:16
Speaker 1: and and astronomers, early astronomers, and so I think, um,
23:20
Speaker 1: without having eclipses, we would have a bit of a
23:22
Speaker 1: different culture. Do you think it would have affected our
23:24
Speaker 1: scientific development? You know, like with having the moon there,
23:28
Speaker 1: God is thinking about planets and orbits and you know,
23:32
Speaker 1: bodies and mass and motion, right, because didn't Newton sort
23:36
Speaker 1: of used the moon in his thinking about gravity. Absolutely,
23:40
Speaker 1: I think it's vital because there's this incredible step in
23:44
Speaker 1: human history and physics that that Newton accomplished, connecting motion
23:49
Speaker 1: of stuff on Earth to motion of stuff in the sky, right,
23:51
Speaker 1: to say, maybe the same rules that apply here on
23:54
Speaker 1: Earth also apply to stuff in the sky. And that's
23:57
Speaker 1: a much easier leap to make if you can see
23:59
Speaker 1: stuff in the sky that seems concrete, right, The stars
24:02
Speaker 1: and all that stuff, they're just tiny dots. You have
24:05
Speaker 1: no idea that they're really things, or they're just lights
24:07
Speaker 1: up in some some ceiling. But the moon looks like
24:10
Speaker 1: a thing, right, it looks like a big rock. It's immediate,
24:13
Speaker 1: it's there, And so I think it's very helpful for
24:16
Speaker 1: early thinkers to understand that the stuff out there in
24:19
Speaker 1: the sky was just more like the stuff here on earth.
24:22
Speaker 1: Maybe God's thinking that maybe this guy is not just
24:24
Speaker 1: a big canvas with pinpoints on them, right, Like, maybe
24:27
Speaker 1: there are there are things out there and we and
24:30
Speaker 1: we can understand them, right, they follow the rules that
24:33
Speaker 1: we can figure out. That's an incredible moment in the
24:35
Speaker 1: history of like human intellectual thought, right, that we could
24:38
Speaker 1: understand the cosmos all right, So no eclipses smaller tides.
24:43
Speaker 1: What else would happen if we said good night, Yeah,
24:47
Speaker 1: well we would have darker nights. Right. The moon is
24:50
Speaker 1: basically a big mirror for the sun, and so when
24:52
Speaker 1: the sun is on the other side of the planet,
24:54
Speaker 1: the moon provides a little bit of reflection of the
24:56
Speaker 1: Sun's light. And so you know, we've all been out
24:59
Speaker 1: on a on the night when you have a full
25:01
Speaker 1: moon and it's much easier to see. And there's a
25:04
Speaker 1: lot of animals that rely on the moon. But it
25:07
Speaker 1: affects some animals in a good way and some in
25:09
Speaker 1: a bad way. Right. Yeah. For example, some animals like owls, right,
25:13
Speaker 1: they hunt at night, right, and they use the moonlight.
25:16
Speaker 1: They have very powerful eyes. But they need some light,
25:18
Speaker 1: and so owls have to hunt by only starlight, then
25:21
Speaker 1: you know they're not going to find as many rats.
25:24
Speaker 1: And so conversely, getting rid of the moon would be
25:27
Speaker 1: good for rats because they've mostly come out at night
25:32
Speaker 1: to find their food and their main predator is owls,
25:36
Speaker 1: and so if it's darker than it's easier to scurry
25:38
Speaker 1: along and you know, find that pizza on the on
25:40
Speaker 1: the New York subway or whatever. So if you are
25:42
Speaker 1: a pro rat, this would be a good thing. If
25:44
Speaker 1: your pro owls. You make that sound like pro rat
25:47
Speaker 1: is impossible, I am pro rat, because no I am.
25:53
Speaker 1: You may not be aware, but we actually have rats
25:55
Speaker 1: as pets at home. Yeah, yeah, I think I remember.
25:58
Speaker 1: So rats are very sweet, very purpose We got them
26:01
Speaker 1: on purpose. Yes, um, they're very sweet, very intelligent, very loving,
26:07
Speaker 1: very smart little creatures. Actually, all right, so you're in
26:10
Speaker 1: the pro And also because while the moon played some
26:14
Speaker 1: role in, you know, helping us think about the cosmos,
26:17
Speaker 1: it's actually kind of annoying from an astronomical point of
26:20
Speaker 1: view because you can ruin a nice dark night, which
26:24
Speaker 1: is you couldn't You can't see the stars very well. Yeah,
26:27
Speaker 1: like I've gone camping sometimes, and one of my favorite
26:29
Speaker 1: things by camping, he's getting to look up at the
26:31
Speaker 1: night sky and seeing a really dark night, because it's
26:34
Speaker 1: incredible how many stars are out there, right, And most
26:36
Speaker 1: people who live in big cities, they have no idea
26:39
Speaker 1: how many stars are visible in the night sky. But
26:41
Speaker 1: when you go out in the middle of nowhere and
26:43
Speaker 1: you're far from everything and you can finally see the
26:45
Speaker 1: Milky Way in all of its beautiful glory. But then
26:47
Speaker 1: there's the moon and all you can see is the
26:50
Speaker 1: moon and nothing else, you know, watching it exactly, and
26:53
Speaker 1: so us for romantic physicists, it's beautiful. No, you're right.
26:58
Speaker 1: I was just a cat thing the other day, and
27:01
Speaker 1: you know, I remember looking up and seeing the milk
27:03
Speaker 1: away and it was amazing, and my kids were super impressed.
27:08
Speaker 1: I hadn't thought about it back then, but you're right.
27:09
Speaker 1: I think it was a moonless night, and if the
27:11
Speaker 1: moon happened out, we we wouldn't have seen these things.
27:14
Speaker 1: All right. Let's get into what else would happen if
27:18
Speaker 1: we lost the moon, And this one is a little
27:20
Speaker 1: bit more serious. I have to say it would actually
27:23
Speaker 1: affect you on a daily basis. But first let's take
27:27
Speaker 1: a quick break, all right. We're talking about what would
27:41
Speaker 1: happen if the moon disappeared, and we've talked about smaller tides,
27:45
Speaker 1: no eclipses, which would be a bummer for poets and
27:49
Speaker 1: um ancient civilizations perhaps, and darker nights. But there is
27:54
Speaker 1: sort of a serious consequence to having no moon, right, yeah, exactly.
27:59
Speaker 1: This is a bit of speculation based on modeling people
28:02
Speaker 1: have done, But it seems like having a moon plays
28:05
Speaker 1: a big role in the Earth's rotation and in its tilt. Right,
28:09
Speaker 1: So the Earth spins around once a day, but it's
28:12
Speaker 1: also tilted off of its axis, right, which is why
28:15
Speaker 1: we have seasons. Like sometimes you're tilted a little bit
28:18
Speaker 1: closer to the sun, sometimes you tilt a little further
28:20
Speaker 1: from the Sun. And so the Earth's rotation controls the
28:23
Speaker 1: length of the day, and it's tilt controls the the
28:26
Speaker 1: magnitude of our seasons. And as we were talking about before,
28:30
Speaker 1: the Earth and the moon are part of a complicated
28:32
Speaker 1: system of anglar momentum, and and it seems like having
28:36
Speaker 1: a moon makes the Earth's situation a little bit more stable.
28:41
Speaker 1: Like planets without a moon, it's easier for their tilt
28:44
Speaker 1: to change, like we could the way we're spinning around
28:48
Speaker 1: in place, not just around the Sun, could change, like
28:51
Speaker 1: we could tilt more towards the Sun or away from this. Yeah, exactly.
28:55
Speaker 1: We're more susceptible, for example, being struck by rocks or
28:59
Speaker 1: this kind of stuff. And the only way we could
29:01
Speaker 1: absorb the angular momentum of some like impact or something
29:04
Speaker 1: would be by the Earth changing its tilt or changing
29:07
Speaker 1: its rotation speed. But if you have a moon, you
29:09
Speaker 1: have a more complicated system that can absorb it in
29:12
Speaker 1: other ways. And so you know, if it's some big buffer,
29:15
Speaker 1: it's like a gravitational buffer. Yeah exactly, it's like a
29:18
Speaker 1: gravitational buffer, and you can dump some of that stuff
29:21
Speaker 1: into the moon, like well, make the moon spin faster
29:23
Speaker 1: or make the Moon go around a little faster or whatever,
29:26
Speaker 1: and so without affecting that. Yeah, And so it seems
29:29
Speaker 1: like having a moon makes the whole system a little
29:31
Speaker 1: bit more stable for the Earth. So you know, we
29:33
Speaker 1: could end up like if we lost our moon, we
29:36
Speaker 1: could end up in a situation where we have no tilt, right,
29:38
Speaker 1: which means we have like no seasons, right, because the
29:41
Speaker 1: tilt is what gives you seasons, right, yeah, exactly. The
29:44
Speaker 1: tilt of the Earth relative to the Sun means sometimes
29:49
Speaker 1: the people in the north are closer to the Sun,
29:51
Speaker 1: and sometimes means they're further away from the Sun. Right, Yeah,
29:54
Speaker 1: So if we lost our moon, we'd lose a bit
29:55
Speaker 1: of our gravitational angle momentum buffer, and we'd be more
29:59
Speaker 1: susceptible to some of these big changes, which could have
30:01
Speaker 1: like obviously huge effects on the climate and survivability of
30:05
Speaker 1: the Earth, well beyond whether rats can get gobbled up
30:08
Speaker 1: by owls or whether or not Jorge can see the
30:11
Speaker 1: Milky Way on his camping trip. There will be no seasons,
30:14
Speaker 1: or there could be crazy extreme seasons, which and maybe
30:17
Speaker 1: that those kinds of things wouldn't support light, right, it
30:20
Speaker 1: would be Um, it would be a big deal. Yeah,
30:23
Speaker 1: all right, Daniel, So, um, those are all pretty cool. Um,
30:27
Speaker 1: but I'm a little bit worried now should I be worried?
30:29
Speaker 1: Is the moon going to be going away anytime soon?
30:32
Speaker 1: All these things are fun to think about, you know,
30:35
Speaker 1: interesting to sort of probe the physics of the situation,
30:38
Speaker 1: But none of these things are very likely to happen. Right,
30:41
Speaker 1: We've been watching the skies for a long time. We're
30:43
Speaker 1: pretty sure that there are no big rocks headed for
30:47
Speaker 1: us that are likely to obliterate the Moon. It would
30:50
Speaker 1: be pretty surprising if that happened. As long as we
30:52
Speaker 1: are friendly to the programmers who run the stimulation and
30:55
Speaker 1: they don't just decide to delete the Moon from our existence,
30:59
Speaker 1: then I think we can on having the Moon for
31:01
Speaker 1: you know, a lot longer. In fact, I was thinking
31:03
Speaker 1: it would be kind of a best case scenario. Actually,
31:05
Speaker 1: if like an asteroid hits the Moon and knocks it
31:08
Speaker 1: out of orbit, that's like a good thing because it
31:10
Speaker 1: means that then it hit hit up exactly exactly. We
31:13
Speaker 1: sort of use up our buffer on that one asteroid
31:16
Speaker 1: and we'd be totally vulnerable to the next one. Be
31:19
Speaker 1: like those movies where the bullet it is headed is
31:21
Speaker 1: headed towards you, but then somebody runs in and inters,
31:25
Speaker 1: that's right exactly, and you lose that person, but at
31:28
Speaker 1: least you didn't get shot the target. Greats are like,
31:30
Speaker 1: we'll save you, that's right. So maybe thanks to the
31:36
Speaker 1: Israelis for founding the lunar colony. Cool. But I'd imagine
31:43
Speaker 1: also that even if we lost the Moon through whatever reason,
31:48
Speaker 1: it doesn't sound like immediate death for us. You know,
31:51
Speaker 1: it would mean changes in patterns and tides and seasons,
31:55
Speaker 1: but maybe not immediate like we're dead in the war. Yeah,
31:58
Speaker 1: it would not be immediate death. We have some time
32:00
Speaker 1: to adjust and you know, even if the earth seasons
32:03
Speaker 1: get more dramatic, we'll figure it out. You know. Think
32:06
Speaker 1: about the careful, considered way that we're dealing with climate
32:09
Speaker 1: change right now. Doesn't that give you confidence that we'll
32:11
Speaker 1: be able to handle something like that? Sarcasm, sarcasm, sarcasm,
32:17
Speaker 1: that's what a sarcastic physicistm There you go. No, but
32:20
Speaker 1: this is definitely solidly in the fun to think about
32:23
Speaker 1: but not actually worry about category. All right, Well, so
32:27
Speaker 1: if you're a rat lover you can rest at ease.
32:30
Speaker 1: Then all those rats out there are no, wait, you
32:34
Speaker 1: should be worried. You don't need to worry about. Sorry.
32:38
Speaker 1: If you're a rat lover, then uh, I'm sorry. We
32:41
Speaker 1: can can't get me any time. You know what, rats
32:42
Speaker 1: are going to survive longer than we are, I think.
32:44
Speaker 1: All right, thanks for tuning in, and thank you for
32:47
Speaker 1: sending these fascinating questions. If you have a question about
32:50
Speaker 1: a crazy hypothetical situation, you'd like us to work out
32:52
Speaker 1: in details, send it to us at questions at Daniel
32:56
Speaker 1: and Jorge dot com. So in the meantime, go out
32:58
Speaker 1: there and look at the moon and appreciate its beauty
33:02
Speaker 1: or its absence if you want to be at the stars.
33:04
Speaker 1: And that's right and the Milky Way. Moons are something
33:08
Speaker 1: you never appreciate until you lose them. I hope you
33:10
Speaker 1: enjoyed it, See you next time. If you still have
33:19
Speaker 1: a question after listening to all these explanations, please drop
33:23
Speaker 1: us a line. We'd love to hear from you. You
33:25
Speaker 1: can find us at Facebook, Twitter, and Instagram at Daniel
33:28
Speaker 1: and Jorge that's one word, or email us at Feedback
33:32
Speaker 1: at Daniel and Jorge dot com. Thanks for listening and
33:35
Speaker 1: remember that Daniel and Jorge Explain the Universe is a
33:38
Speaker 1: production of I Heart Radio. For more podcast from my
33:42
Speaker 1: Heart Radio, visit the I Heart Radio app, Apple Podcasts,
33:45
Speaker 1: or wherever you listen to your favorite shows. Yeah